ERICA JONG has just finished chatting with fellow author Joanna Trollope on Radio 4's Woman's Hour, and has tripped across the road from the BBC's Broadcasting House, back to London's Langham Hotel opposite, to meet me in the bar.
Her throat, understandably, is dry and, as she takes a window seat, rather than ordering a cocktail or glass of wine, as she may have done once, she sends an assistant out to find some lozenges.
At 73, she's finding the tour for her new book Fear Of Dying tiring, and admits: "Whenever I get back to the hotel, I just crash with exhaustion."
Her first novel in more than a decade (she's recently been writing poetry), it's a follow-up of sorts to 1973's Fear Of Flying, which has sold more than 27 million copies and made Jong a celebrity Second Wave feminist, on a par with Germaine Greer and Gloria Steinem. Where that book, shockingly back then, followed Isadora Wing's search for the perfect no-strings sex, this one is about a woman and friend of Isadora's, in her sixties dealing with parents dying, a pregnant daughter and sick husband.
"It's a stage of life that is very intense and very emotional," Jong says, pushing blue horn-rimmed shades back into her blonde hair.
She remembers how her first editor said, 'You know, there's never been a bestseller about a woman over 40'.
"This was years ago – and the first thing I said was, 'Then I should write it.' It's been in my head a long time, but we're not hearing about these further stages of women's lives, which are so interesting."
Fear Of Dying centres on Vanessa Wonderman, an ageing actress, whose 80-something husband is left impotent after an aneurysm and whose once-powerful parents are ebbing away. To cope with the emotional upheaval – and to try and turn the clock back – she signs up to Zipless.com, a site similar to Tinder, in search of sex – which throws up some funny and, frankly, disturbing results.
If women wanting sex without commitment was taboo in the 1970s, women in their sixties wanting sex at all is swept under the carpet in society today.
"But they do!" protests Jong, who's blissfully happy with her fourth husband, a lawyer and her "soulmate" Ken.
"It's not that they don't have it, it's that it's taboo to write about it. There's this privacy thing in Britain which often results in a kind of hypocrisy. People do it, but they don't talk about it."
Neither do we really talk about death.
"There's a wonderful Italian proverb, which goes like this, 'At the end of the game, both king and porn go in the same box'. I mean, what could be more clear? However much power you have, you're going to wind up in a box."
Jong based much of Fear Of Dying on her own experiences of being a wife, mother and daughter – and watching her parents slowly fade.
"When my mother died, she was incredibly peaceful. She was 101, she was really ready," she says.
"My father was the one who fought against time. I saw him being the health freak, getting on the treadmill as if he could not die, and it was really sad in a way, because he had that male thing of, 'I can do whatever I want'. But you really can't. I saw them both approach life and death differently, which was fascinating."
In her original draft, Jong's protagonist Vanessa found a way to go back to being 30 again "by magic".
"I tried to imagine getting her wish to look 30, but knowing what she knows at 60. It seemed very artificial, so I tore up that draft of the book," she says, looking glamorous in a burgundy cowl-necked sweater with chunky turquoise beads and a sky-blue coat.
"I wouldn't swap. I believe humans are spiritual beings encased in a fleshly body – and the body is very much a part of our being. I wouldn't reverse time, I accept time. It's not easy, but I do."
Life has not always been straightforward for Jong, but she's got through the tough times with "grit and humour", she says, laughing. Born in New York, the middle daughter of a painter mother and porcelain doll-maker father, she married her college sweetheart, who was schizophrenic, and their marriage was annulled.
"He was so smart and so lovely and so imaginative, but the marriage came apart..."
In the late sixties, she lived on an army base in Germany with her second husband, psychiatrist Allan Jong, a period she wrote about in Fear Of Flying.
Her only daughter Molly, from her third marriage to novelist Jonathan Fast, struggled with addiction, and now has three children to whom Jong is a doting grandma.
She remains on good terms with Fast and they even take holidays together as a family.
"We sit on the floor and do Lego with our grandchildren," she says, smiling.
"I'm a witness to his life, he's a witness to mine – I wouldn't want to lose that."
She says it's been "miraculous" watching her twin grandchildren, a girl and a boy, grow up – and her granddaughter is already a young feminist.
"My granddaughter says to me, 'I went to school today and they told us that women were slaves in many countries, is this true? We have to change that'.
"Smart little girls mature much faster than their brothers. Her twin brother Darwin has meltdowns at seven, she hasn't had a meltdown since she was three. And when Darwin has a meltdown, she turns to me and her mother and says, 'He's not an easy child is he?'" she says, chuckling.
Since Fear Of Flying was first published, the world has changed enormously, there's the internet for one, but Jong believes it still "hasn't changed enough" for women – and is backing Hilary Clinton's campaign to be the first female US president.
"If you want to see an encapsulated version of why it's not enough, look at the way Hilary Clinton is treated in the press. Look at the fact America has not yet had a female president. Look at the fact she's daily slandered in even our most supposedly intellectual papers..."
She rails against modern "mummy Nazis" who try and dictate how mothers should give birth and look after their children: "I think the sort of feminism that tries to preach to women the way you must do things, is the antithesis of real feminism: real feminism's about choice."
Jong is active on Twitter and likes Instagram for the "beautiful images", but thinks social media is ultimately disappointing as a way of meeting people.
"I never looked for sex on the internet, but people tell me their love stories all the time. I can't get on a plane without somebody telling me about their sex life, right?" she says with a wry smile.
"People are very disappointed with the internet as a way of finding love, sex or romance. So in a way, I'm satirising the dream in my book.
"My daughter met her husband on JDate and they have a very good marriage, but that was 12 years ago, and I think people are very disillusioned with social media. It doesn't tell the truth, it's all about images and I don't think there's reality there. A lot of it is about monetising your life. I don't trust it."
Jong's own experiences of the tough side of celebrity have put her daughter, also a writer, off wanting to be famous.
"She saw what fame had done in my life and said, 'It's not that great, people following you around, writing false things about you'. She was invited to be on the reality show Housewives Of New York and she could have made a lot of money.
"But she said, 'I don't want to expose my children to all the bullshit that comes with that kind of idiotic fame'. Which is amazing. She's not Kim Kardashian, she will not do anything to get free clothes. I'm very proud of her."
Looking back on her life, Jong has no regrets, although she admits: "There were things I did that were incredibly stupid, who hasn't?"
But she still has fears.
"I certainly don't want to become ill or lose my mind. I would like to go on writing about older women and older men, because it's so fascinating. I have many books in my head and I hope I have the power to write them."
:: Fear Of Dying by Erica Jong is published in hardback by Canongate Books, priced £16.99 (ebook £7.49). Available now
